UIScrollView is something that can be very confusing because it uses constraints in a way that they aren't normally used. Because of this there is so much confusion.

Implementing a UIScrollView is actually really easy when you know/do three fundamental things. There is a video I uploaded that walks you through this process UIScrollView Video but incase you forget you can use the following as a reference.

Use a View (let's call it, ContentView) in your ScrollView to keep the layout of . . .

Two design patterns which can be used to implement Singletons in Swift.

The Singleton pattern makes sure only one instance of a given class exists. Usually that single instance is lazily loaded when it is needed. There are a bunch of examples of this built into iOS such as:

How various iOS apps implement SMS/Text based sharing. We consider the pros and cons of each.

When a requirement to be able to sms/text users in the address book of the user of an app is necessary there are different implementation methods that we see in various apps.
Here we consider how the user chooses the addresses to include in the sms/text message. We also consider the pros and cons of each option as well as look at a list . . .